getdp for Debian ---------------- Options for PETSc can be provided on the command line, or in the file ~/.petscrc. By default we try to use the MUMPS or UMFPACK direct solver (if available, with PETSc 3). Otherwise we use a GMRES iterative solver preconditionned with an ILU(6). All these options can be changed at runtime. For example you could use -pc_type ilu -pc_factor_levels 0 -ksp_rtol 1.e-6 -ksp_gmres_restart 500 -ksp_monitor for GMRES with ILU(0), with a restart of 500 and a stopping criterion of 1e-6. Or you could set -pc_type lu -pc_factor_mat_solver_package mumps -ksp_type gmres to use the MUMPS direct solver as a preconditioner to GMRES (useful e.g if the matrix changed a bit, but you want to keep the same factorization using "SolveAgain"). -- Christophe Trophime Thu, 27 Aug 2009 13:09:50 +0200